XCreateColormap(3X11)	       XLIB FUNCTIONS		XCreateColormap(3X11)



NAME
  XCreateColormap, XCopyColormapAndFree, XFreeColormap, XColor - create,
  copy, or destroy colormaps and color structure

SYNTAX
  Colormap XCreateColormap(display, w, visual, alloc)
	Display *display;
	Window w;
	Visual *visual;
	int alloc;

  Colormap XCopyColormapAndFree(display, colormap)
	Display *display;
	Colormap colormap;

  XFreeColormap(display, colormap)
	Display *display;
	Colormap colormap;

ARGUMENTS

  alloc	    Specifies the colormap entries to be allocated.  You can pass
	    AllocNone or AllocAll.

  colormap  Specifies the colormap that you want to create, copy, set, or
	    destroy.

  display   Specifies the connection to the X server.

  visual    Specifies a visual type supported on the screen.  If the visual
	    type is not one supported by the screen, a BadMatch error
	    results.

  w	    Specifies the window on whose screen you want to create a color-
	    map.

DESCRIPTION
  The XCreateColormap function creates a colormap of the specified visual
  type for the screen on which the specified window resides and returns the
  colormap ID associated with it.  Note that the specified window is only
  used to determine the screen.

  The initial values of the colormap entries are undefined for the visual
  classes GrayScale, PseudoColor, and DirectColor.  For StaticGray, Sta-
  ticColor, and TrueColor, the entries have defined values, but those values
  are specific to the visual and are not defined by X.	For StaticGray, Sta-
  ticColor, and TrueColor, alloc must be AllocNone, or a BadMatch error
  results.  For the other visual classes, if alloc is AllocNone, the colormap
  initially has no allocated entries, and clients can allocate them.  For
  information about the visual types, see section 3.1.

  If alloc is AllocAll, the entire colormap is allocated writable.  The ini-
  tial values of all allocated entries are undefined.  For GrayScale and
  PseudoColor, the effect is as if an XAllocColorCells call returned all
  pixel values from zero to N - 1, where N is the colormap entries value in
  the specified visual.	 For DirectColor, the effect is as if an XAllocColor-
  Planes call returned a pixel value of zero and red_mask, green_mask, and
  blue_mask values containing the same bits as the corresponding masks in the
  specified visual.  However, in all cases, none of these entries can be
  freed by using XFreeColors.

  XCreateColormap can generate BadAlloc, BadMatch, BadValue, and BadWindow
  errors.

  The XCopyColormapAndFree function creates a colormap of the same visual
  type and for the same screen as the specified colormap and returns the new
  colormap ID.	It also moves all of the client's existing allocation from
  the specified colormap to the new colormap with their color values intact
  and their read-only or writable characteristics intact and frees those
  entries in the specified colormap.  Color values in other entries in the
  new colormap are undefined.  If the specified colormap was created by the
  client with alloc set to AllocAll, the new colormap is also created with
  AllocAll, all color values for all entries are copied from the specified
  colormap, and then all entries in the specified colormap are freed.  If the
  specified colormap was not created by the client with AllocAll, the alloca-
  tions to be moved are all those pixels and planes that have been allocated
  by the client using XAllocColor, XAllocNamedColor, XAllocColorCells, or
  XAllocColorPlanes and that have not been freed since they were allocated.

  XCopyColormapAndFree can generate BadAlloc and BadColor errors.

  The XFreeColormap function deletes the association between the colormap
  resource ID and the colormap and frees the colormap storage.	However, this
  function has no effect on the default colormap for a screen.	If the speci-
  fied colormap is an installed map for a screen, it is uninstalled (see XUn-
  installColormap).  If the specified colormap is defined as the colormap for
  a window (by XCreateWindow, XSetWindowColormap, or XChangeWindowAttri-
  butes), XFreeColormap changes the colormap associated with the window to
  None and generates a ColormapNotify event.  X does not define the colors
  displayed for a window with a colormap of None.

  XFreeColormap can generate a BadColor error.

STRUCTURES
  The XColor structure contains:

  typedef struct {
       unsigned long pixel;/* pixel value */
       unsigned short red, green, blue;/* rgb values */
       char flags;	   /* DoRed, DoGreen, DoBlue */
       char pad;
  } XColor;

  The red, green, and blue values are always in the range 0 to 65535
  inclusive, independent of the number of bits actually used in the display
  hardware.  The server scales these values down to the range used by the
  hardware.  Black is represented by (0,0,0), and white is represented by
  (65535,65535,65535).	In some functions, the flags member controls which of
  the red, green, and blue members is used and can be the inclusive OR of
  zero or more of DoRed, DoGreen, and DoBlue.

DIAGNOSTICS

  BadAlloc  The server failed to allocate the requested resource or server
	    memory.

  BadColor  A value for a Colormap argument does not name a defined Colormap.

  BadMatch  An InputOnly window is used as a Drawable.

  BadMatch  Some argument or pair of arguments has the correct type and range
	    but fails to match in some other way required by the request.

  BadValue  Some numeric value falls outside the range of values accepted by
	    the request.  Unless a specific range is specified for an
	    argument, the full range defined by the argument's type is
	    accepted.  Any argument defined as a set of alternatives can gen-
	    erate this error.

  BadWindow A value for a Window argument does not name a defined Window.

SEE ALSO
  XAllocColor(3X11), XChangeWindowAtrributes(3X11), XCreateWindow(3X11),
  XQueryColor(3X11), XStoreColors(3X11)
  Xlib - C Language X Interface